Troubleshooting ​

CAUTION

Experimental — not for production. Managed Data Mode SSR is available for evaluation and testing. Do not use it in production yet. The API and behaviour may change. Until then, continue using Webpack SSR.

Common Managed Data Mode SSR issues and fixes. Found an issue that this page does not cover? Report it via support so we can help and expand this guide.

CJS default-export interop ​

CommonJS (CJS) is the older Node module format that uses module.exports. Some CommonJS packages expose both a default and named exports. Under SSR sku start, importing such a package as a React component can resolve to a module namespace object ({ default: ActualComponent, … }). React then fails with:

text
Element type is invalid: expected a string … but got: object.
You likely forgot to export your component … or you might have mixed up default and named imports.

Production sku build may still succeed for the same import. The failure is often start-only.

Add the package name to __UNSAFE_EXPERIMENTAL__cjsInteropDependencies (sku already includes Apollo Client in its defaults):

ts
// sku.config.ts
import type { SkuConfig } from 'sku';

export default {
  bundler: 'vite',
  buildType: 'ssr',
  __UNSAFE_EXPERIMENTAL__cjsInteropDependencies: [
    'react-helmet-async',
    'some-legacy-cjs-ui-kit',
  ],
} satisfies SkuConfig;

Prefer upgrading to an ESM build or replacing the dependency when possible.

See also ​